Apparatus for indicating the level of charges in furnaces.



No. 680,490. Patented Aug. l3, I901.

T. H. MARTIN. APPARATUS FOR INDIYCATING THE LEVEL OF CHARGES IN FURNACES.

{Application filed Mar. 2, 1901.)

(No Model.)

in v 872 601:

JZMMW 9% tin 65666 6/3. QKM 9&3.

UNITED STATES PATENT EEIoE.

THOMAS H. MARTIN, OF CLEVELAND, OHIO, ASSIGNOR OF TWO-THIRDS TO FREDERICK L. GROMMER AND ALBERT T. DE FOREST, OF SAME PLACE.

APPARATUS FOR lNDiCATlNG THE LEVEL OF CHARGES lN FURNACES.

SPECIFICATION formingpart of Letters Patent N0. 680,490, dated August 13, 1901.

Application filed March 2, 1901. Serial No. 49,531. (No model.)

To all whom it may concern:

Be it known that I, THOMAS H. MARTIN, a

citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have. invented a certain new and useful Improvement in Apparatus for Indicating the Level of Charges in Furnaces, of which the following is a full, clear, and exact descrip' tion, reference being had to the accompanying drawings.

The object of this invention is to provide simple and efficient means for indicating the level of the charge in a furnace.

The invention is especially applicable to mechanical means governed from the ground;

but in order that the furnace may not be too" full and that the charge may be approximately regular it has been customary to keep a man at the top of the furnace, who inserts a pole periodically into the furnace, and thus ascertains the approximate level. This not only requires the services of an extra employee on each turn, but it is a dangerous 0ccupation for him, as he is liable to be overcome by the gases and sometimes falls to the ground or into the hopper. In either style of furnace, however, the best that has been done is to ascertain a rough approximation of the general height of the load, and the result has not been entirely satisfactory, asin order to obviate the danger of overcharging the furnace, thus choking the gas hole or preventing the bell reseating, the furnace has been uniformly undercharged, and hence its efficiency decreased.

My invention consists of applying to the furnace an electrically-operated signal and such circuits and terminals that the circuit is governed by the charge when it reaches a certain point. In applying this to a blast-furnace, as the material of the charge is more or less lumpy and is only approximately level, I provide a plurality of electrodes around the furnace operating in independent pairs, whereby the general level of the charge may be observed by the signals.

The invention consists of such an arrangement and operation, broadly, as above explained and more specifically as shown in the drawings and hereinafter described in detail, all of whichis fully set out in the claims.

In the drawings, which fully illustrate the preferred form of my invention, Figure 1 represents a blast-furnace in elevation, its upper part being in section and showing my invention as applied to the same, but with some of the circuits incomplete, as will appear. Fig. 2 is a plan of the same, showing said circuits complete. Fig. 3 is an enlarged section showing the construction of the terminals and the means for insulating the same from the furnace-body.

Referring to the parts by letters, A represents a blast-furnace of any common form, having, however, a contracted throat (t, which may be provided with the usual hopper a and bell Q The furnace, as is usual, is provided with a fire-brick lining a and a retaining outer wall d of sheet-steel.

In applying my invention to such a furnace as I have described I provide a plurality of openings of in the furnace-top, which may be vertical, and within each is fixed an iron pipe B. This pipe carries within its bore a projecting rod T, which may be of steel, and packing C, of suitable non-conducting fireproof material, such as asbestos, serves to insulate this rod from the pipe B. A large washer C, of non-conducting material, may support the head i of the rod T. Each of the rods T may be provided with a binding-post t, to which electric wires attach, so that these rods may form electric terminals. These rods are connected in pairs in a circuit including a source of current and a signal, such as an incandescent lamp. Now when the charge in the furnace reaches the maximum height the coke or the ore will bridge the distance across the pairs of electrodes and complete the circuit, thus causing the lamp to light, and the height of the charge at the point will be known. If one or more of the signals require a material charge to cause their lighting after others have lighted, it will indicate that the charge is not being properly apportioned to the various parts of the furnace. The electrodes '1, being uncovered for a considerable distance from their lower ends, do not require the contact at their extreme ends, wherefore if there should happen to be limestone in the charge at the extreme end of the electrode the contact will soon be made by coke or ore at the side of it, and this will be a close enough approximation for all practical purposes.

Vith the circuits as arranged in the draw ings, G represents a batteryor generator, from which run main conductors \/V w. The mains have, respectively, the branches \V' lV W and to w re". The branches in, 70 and 10 run, respectively, to alternate terminal rods '1", T and T and they carry, respectively, the electric lights L, L and L Evidently if any one of the intermediate terminal rods T is in contact with the charge J and one of the terminal rods T, T or T contacts with the charge also the corresponding light will become incandescent. Thus suppose the terminal rod 1 and the one immediately to its right make contact with the charge. The light L will become incandescent immediately, the circuit being as follows: by branch WV, main \V, generator G, main to, branch 10 light L terminal rod T to the charge J, to first terminal.

What I claim is 1. The combination of a furnace, a pair of electric terminals in the interior thereof, an electric circuit leading from said terminals and including a source of current and a signal the same being arranged so that the circuit is closed by the conductive charge in the furnace bridging from one of said terminals to the other, substantially as described.

2. The combination of a furnace having an opening near its threat, a pair of insulated rods mounted therein, an electric circuit including a source of current and a signal connected to said rods and arranged so that the circuit is closed when the conductive charge bridges said rods, substantially as described.

The combination with a blast-furnace, of a plurality of electrodes extending thereinto and arranged approximately regularly around the upper part thereof, electric cir} cuits leading therefrom including a source of current, and signals whereby the approximate general level of the load across the fur nace may be determined, substantially as de= scribed.

4. The combination with a blast-furnace having at its upperend a central charge-opening, a plurality of rods arranged around said charge opening and projecting downward into the interior, means for insulating said rods from the metallic part of the furnace, a series of signals, and a source of current, and suitable electric connections whereby when the conductive charge bridges pairs of elee' trodes the signal is operated.

5. The combination of a blast-furnace, a plurality of insulated rods extending thereinto and arranged approximately regularly thereabout, a source of current, a system of branch conductors from said sou rce leading to alternate members of said rods, electric signals on said branches, the intermediate rods being connected with the other side of the source of current, substantially as described.

6. In combination with a blast furnace having openings near its top, pipes mounted in said openings, projecting rods carried in said pipes respectively, insulated packing around said rods, electric circuits, said rods forming terminals for the same, and electric signals in said circuits, substantially as described.

' In testimony whereof I hereunto affix my signature in the presence of two witnesses.

THOMAS H. MARTIN. WVitnesses:

ALBERT H. Barns, II. M. Wrsn.

It is hereby certified that the name of the first-mentioned assignee in Letters Patent No. 680,490, granted August 13, 1901, upon the application of Thomas H. Martin, of

Cleveland, Ohio, for an improvement in Apparatus for Indicating the Level of Charges in Furnaces, was erroneously Written and printed Frederick L. Grommer,

Whereas said name should have been written and printed Frederick L. Grcmimer; and

that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed, countersigned, and sealed this 3d day of September, A. DJ, 1901.

[SEAL] F. L. CAMPBELL,

Assistant Secretary of the Interior. Countersigned E. B. MOORE,

Acting Commissioner of Patents.

It is hereby certified that the name of the first-mentioned assignee in Letters Patent No. 680,490, granted August 13, 1901, upon the application of Thomas H. Martin, of

Cleveland, Ohio, for an improvement in Apparatus for Indicating the Level of Charges in Furnaces, was erroneously written and printed Frederick L. Gromnier,

whereas said name should have been written and printed Frederick L. Grammar; and

that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed, countersigned, and sealed this 3d day of September, A. DJ, 1901.

F. L. CAMPBELL,

[SEAL] Assistant Secretary of the Interior.

I Countersigned E. B. MOORE,

' Acting Ommnissioner of Patents. 

